Alternator Cutoff Switch

spark will be weaker, and i personally dont think it will make a difference by unplugging it, what will make a difference is bypassing your a/c and smog pump with a shorter belt, try that.
 
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I dont have a smog pump and bypassing the a/c wont help anything as it has a clutch on it the allows it to freewheel (no drag). Thanks for your input Black70Fastback. The last thing im worried about is frying a computer. I dont know how much it'll help but it can't hurt. The real drag cars do it and they dont have a weak spark problem. Guess we'll find out. Thanks
 
as long as the ac is off, its just another idler pulley and maybe 2.5 ounces of rotating wieght if you want to be picky. obvioulsy if you removed the whole unit, it would be a wieght save and yes the smog pump would help to be bypassed.

basically, if people didnt have the balls to try stuff. we wouldnt learn stuff. and racing is all about new ideas and fresh techniques just to get an edge on someone else. im putting money on it not helping him much but im all for him at least trying it. hey, maybe he'll be .10 faster for 2 bucks and some of you guys will be doing the same thing next week
 
Well the battery starts the car then the alternator allows it to run and charges the battery. The battery will stop working once the engine start rolling. In the alternator there's this one thing that prevents spikes. I think its called Diodes, it only allows current to flow one way. If you're just running the car with the battery it might make a spike and can fry your computer. The battery don't have diodes so it can produce spike any time it wants. Get what Im saying?

BTW, those track guys that is doing it is because they probably are non efi and/or have control of their computer with a different programmer.
 
oy, its not like the car shuts the battery off once its running. basically the alt. is hooked up to the posative side of the battery and the car is ran off that. while the alt. is operating, the car should be at 14.4 volts and when its not, it should be at 12 volts. this might hinder injector performance/ignition but minimally and he has to atleast try it

the diodes you speak of are there for the basic principle of an alternator. a diode is one way electric vavle so to speak. the alt. makes an AC or "alternating" current. wierd huh? the diode cuts that down to a DC (direct current) that a car is designed to use.

as far as spikes go, thats what fuses are for. so as long as hes not using the "lincoln fuse" in anything he should be fine. a piece of wire or etc.

lincoln fuse is a term from the old style screw in houshold fuses. when a fuse blew, people would screw it out, put a penny (lincoln) under it and screw it back in. meaning it was hotwired and stuff could be fried or houses could be burned down.
 
Black70Fastback said:
oy, its not like the car shuts the battery off once its running. basically the alt. is hooked up to the posative side of the battery and the car is ran off that. while the alt. is operating, the car should be at 14.4 volts and when its not, it should be at 12 volts. this might hinder injector performance/ignition but minimally and he has to atleast try it

the diodes you speak of are there for the basic principle of an alternator. a diode is one way electric vavle so to speak. the alt. makes an AC or "alternating" current. wierd huh? the diode cuts that down to a DC (direct current) that a car is designed to use.

as far as spikes go, thats what fuses are for. so as long as hes not using the "lincoln fuse" in anything he should be fine. a piece of wire or etc.

lincoln fuse is a term from the old style screw in houshold fuses. when a fuse blew, people would screw it out, put a penny (lincoln) under it and screw it back in. meaning it was hotwired and stuff could be fried or houses could be burned down.
Actually the Rectifer is the thing that change AC current to DC current. Diodes keeps current going in one way. a fuse controls high/unwanted amps, it does not control directional current flow. Have you ever seen or hook up a batter backwards? Some cars it might not do anything but some will striaght fry the computers or wont allow the car to start. Well with no Diodes/no alternator this is what can happen.
 
WOW. OK tripping the field connection on an alternator is an old racers trick and can net you a tenth or more.

Now on EFI cars this may not be the hot ticket as all your sensor readings to the computer may be thrown off as well as the newer cars having elec. fuel pumps as opposed to mech. It is easy and worth a try at the track, usually a throttle switch for WOT to interupt the feild will work. I have also read that it is not a hot ticket for N02 cars as the high pressure soliniods can have a big draw.
 
Disconnecting the main wire to the alternator while the engine is running can cause a voltage spike that can destroy the computer. Disconnecting the field wire won't do anything.

Kurt
 
cb18201 said:
how wont bypassing another pulley help you? you think turning off your alternator will help more then getting rid of one extra thing rotating?

What to get rid of? This is a street car. I was just thinkin of a way to make it a little quicker at the track.... always trying to think of stuff. I'm not losing my power steering and most electric water pumps dont have the hookup for the heaterhoses.
 
LOL you guys are killing me. Stump sure what you are talking about is possible, not sure how much you will gain but I know of a local chevelle that picked up .1 in the 1/8th by completly bypassing the alt. so.......


ignore the haters and go for it.
 
xYoung347x said:
Well the battery starts the car then the alternator allows it to run and charges the battery. The battery will stop working once the engine start rolling. In the alternator there's this one thing that prevents spikes. I think its called Diodes, it only allows current to flow one way. If you're just running the car with the battery it might make a spike and can fry your computer. The battery don't have diodes so it can produce spike any time it wants. Get what Im saying?

BTW, those track guys that is doing it is because they probably are non efi and/or have control of their computer with a different programmer.
I think your talking about the voltage regulator diodes. They're the prime reason you should never jump a vehicle while the other one is still on. The load from two engines will pull too much current across those diodes you're talking about and doesn't do well on there life. OK really off subject there :rolleyes: Point is your right :D
 
There is no reason why you can't. If you are even more daring and only have the car on for a VERY short time, you can even run the car beltless. I don't recommend this but I HAVE seen it done. If you are at the track at night and have to have headlights on then I would keep the alternator.
 
This is not a new Idea. Most guys use a wide open throttle switch on the feild wire.
This will free up horsepower when at full throttle and you will charge at all other times. It is a streetable setup on older card cars, never tried it on an EFI car though.
 
xyoung347x- What do you think a rectyifier is made of? Diodes. As far as I can see, Black70fastback has a full understanding of what this thread is about. Give it a try and let us know. It is as simple as going inle with the field wir, shut the engine off, turn the switch off, restart the car and make the run, you can then just simply turn the switch back on with the car running and you will re-excite the field. I have a degree in Robotics and 14 years electronics experience, i can spot a know not from a mile away, some of you guys don't have a clue. Go get a basic electronics/electrical theory book and read it, then come back and post some good facts for our fellow stangers.